1. Field of the Invention
This invention relates to a method of forming an image on a card and an apparatus therefor, which are capable of printing on the card by an ink jet printing method by using a sublimable dye ink.
2. Prior Art
Conventionally, there have been proposed a method of forming an image on a card of a general type and an apparatus therefor, which print an image on a card by an ink jet printing method by using a sublimable dye ink. In this method and apparatus therefor, after an image is formed on the card by ejecting a dye ink from an ink jet head, a surface printed with the image is subjected to a lamination process to protect the printed image on the card. The lamination process is carried out by covering the whole front surface of the card with a transparent film and conducting thermal pressing of the card and film, followed by cutting off an undesired portion of the transparent film according to the size of the card in a die-cutting fashion. This makes it possible to enhance the abrasion resistance and rub resistance of the card printed with the image so that the printed image is not damaged even if it is frequently used by the user.
However, in the conventional image forming method and apparatus of the above-mentioned kind, a punch die is required for performing the lamination process, and moreover it is difficult to cut off the undesired portion of the transparent film such that the periphery of the card is not damaged by the punch die. Therefore, the size of the card having been subjected to the lamination process becomes necessarily larger than that of the original one, thereby impairing the convenience for the user. To carry out the lamination process without using a punch die, however, it is necessary to coat the transparent film such that it does not extend from the periphery of the card, which makes it impossible to uniformly protect the top surface of the card.
It is an object of the invention to provide a method of forming an image on a card and an apparatus therefor, which are capable of printing an image on a card and protecting the printed image in an appropriate and simplified fashion without changing the size of the card.
To attain the above object, according to a first aspect of the invention, there is provided a method of forming an image on a card, comprising the steps of:
printing an image on a card by an ink jet printing method by using a sublimable dye ink while feeding the card, the card having a substrate layer, an ink-fixing layer laminated on a surface of the substrate layer, and an ink image-receiving layer peelably laminated on a surface of the ink-fixing layer, whereby the sublimable dye ink is caused to be held by the ink image-receiving layer;
conveying the card to a heating source; and
subjecting the card to heat treatment by the heating source to thereby cause diffusion of the sublimable dye ink held in the ink image-receiving layer in the ink-fixing layer and color development to form an image; and
peeling the ink image-receiving layer off the card after the heat treatment.
According to this method, when an image is directly printed on a card by the ink jet printing method by using a sublimable dye ink, ink droplets of the sublimable dye ink are impregnated into the ink image-receiving layer and held therein. In this state, when the card is conveyed to the heating source and heated thereby, the heat treatment causes evaporation and diffusion of the ink deep into the ink-fixing layer as migration particles having sizes at a molecular level, and color development, whereby an image is formed. Then, the ink image-receiving layer is peeled off the card to cause the ink-fixing layer to be exposed. Thus, a card can be produced which is printed with an image with ease with a high durabililty.
Therefore, when the card is printed, the ink image-receiving layer capable of temporarily holding an ejected sublimable dye ink is used as an intermediate medium, so that a clear image printed by the ink jet printing method can be directly transferred to the ink-fixing layer, that is, to the surface of the card. This makes it possible to efficiently form a clear image, and further protect the image by the ink-fixing layer without particularly applying pressure thereto, which enhances the rub resistance of the printed surface.
It should be noted that in the step of heating the card by the heating source, it is preferable to apply heat to the card in a non-contacting fashion. Further, it is preferred that the ink image-receiving layer is formed to be slightly larger than the ink-fixing layer. This makes it possible to properly carry out whole surface or edge-to-edge printing of the card, in the step of printing an image on the card, and also makes it easy to peel off the ink image-receiving layer, in the step of peeling the ink image-receiving layer off the card.
Preferably, the ink-fixing layer and the ink image-receiving layer are formed on each of a front surface and a back surface of the card, and the step of printing includes a first printing step of printing an image on one of the front surface and the back surface of the card while feeding the card, an inverting step of inverting the printed card upside down, and a second printing step of printing an image on another of the front surface and the back surface of the card while feeding the inverted card, and the step of heating includes heating the front surface and the back surface of the card simultaneously by the heating source, the step of peeling includes peeling the ink image-receiving layer off the each of the front surface and the back surface of the card.
According to this preferred embodiment, the card used by the method has the same laminate structure on both of the front surface and back surface thereof, which is formed by laminating the layers in the order of the ink-fixing layer and the ink image-receiving layer on the opposite sides of the substrate layer, such that doubled-sided printing by the ink jet printing method can be effected. In the doubled-sided printing, after an image is printed on an ink image-receiving layer of one surface of the card, the card is inverted upside down to print an image on an ink image-receiving layer of the other surface of the card. The card in this inverted position is sent to the heating source and heated thereby, similarly to the above, whereby the ink is fixed in each ink-fixing layer to form a respective image. By peeling off the ink image-receiving layers to expose the respective ink-fixing layers, it is possible to provide a card having images printed on both surfaces thereof.
This makes it possible to properly perform double-sided printing on a card, and efficiently form images on both surfaces of the card to shorten the whole processing time, since the heat treatment is carried out after printing the images on both sides of the card at a time. In this case, it is preferred that the same ink jet printing apparatus is employed in the first printing step and the second printing step. Further, the peeling of the ink image-receiving layer off the each of the front surface and the back surface of the card may be effected by simultaneously peeling off the ink image-receiving layers on both sides.
Preferably, a fluorine film layer is laminated between the ink-fixing layer and the ink image-receiving layer.
According to this preferred embodiment, after the heat treatment of the card, the ink droplets held in the ink image-receiving layer(s) pass through the fluorine film layer to be diffused and fixed in the ink-fixing layer(s). Further, after the ink image-receiving layer(s) is/are peeled off, the card has fluorine film layer(s) as topmost layer(s) thereof for protecting an image or images fixed in the ink-fixing layer(s). Thus, the image(s) is/are protected by the fluorine film layer(s) similarly to laminating films, whereby the surfaces of the card are made more excellent in weather resistance, light resistance, heat resistance, rub or abrasion resistance, and chemical resistance due to characteristics of the fluorine film layer(s), and assume a high gloss.
Preferably, the ink image-receiving layer is formed of a material which is made easily peelable by application of heat.
According to this preferred embodiment, the ink image-receiving layers are made easily peelable by the step of heating the card. As a result, it becomes possible to peel the ink image-receiving layers off the card very easily. On the other hand, the ink image-receiving layers cannot be peeled off easily before heat treatment, which prevents degradation of ease of handling of the card.
Preferably, the step of heating includes causing the card to pass by the heating source being driven for heating, at a constant speed.
According to this preferred embodiment, since the card is conveyed to pass by the heating source at a constant speed, it is possible to carry out feeding and heating of the card simultaneously and further the whole surface of the card can be heated uniformly. This makes it possible to prevent degradation of quality of print images due to unevenness of heating.
Preferably, the heating source is formed by a halogen lamp.
According to this preferred embodiment, the heating source implemented by a halogen lamp is quickly activated, and hence the time required for the heating process can be shortened. On the other hand, since the halogen lamp is a light source with short wavelengths, heat transmission to the substrate layer of the card can be suppressed. As a result, the surface(s) of the card with the ink image-receiving layer can be properly heated.
To attain the above object, according to a second aspect of the invention, there is provided a method of forming an image on a card having a substrate layer, and an ink-fixing layer laminated on a surface of the substrate layer, comprising the steps of:
printing an image on a transfer sheet by an ink jet printing method by using a sublimable dye ink while unrolling and feeding a roll of the transfer sheet, the transfer sheet having a substrate layer, and an ink image-receiving layer laminated on a surface of the substrate layer, whereby the sublimable dye ink is caused to be held by the ink image-receiving layer;
affixing the transfer sheet to the card by pressure while applying heat thereto, with an image-formed portion of the transfer sheet and the ink-fixing layer of the card being positioned and overlaid upon each other, thereby causing diffusion of the sublimable dye ink held in the ink image-receiving layer in the ink-fixing layer and color development to form an image; and
peeling the transfer sheet off the card by taking up the transfer sheet into a roll.
According to this method, a transfer sheet having an ink image-receiving layer formed thereon is employed to form a print image on the card. When an image is directly printed on the transfer sheet by the ink jet printing method by using a sublimable dye ink, ink droplets of the sublimable dye ink are impregnated into the ink image-receiving layer and held therein. Then, a portion formed with the image in the form of the ink droplets is positioned on the card, and the transfer sheet is affixed to the card by pressing the transfer sheet onto the card (contact bonding) in a state of the sheet and card overlaid upon each other while applying heat thereto, whereupon from the portion formed with the image, particles of ink at a molecular level are thermally transferred or migrated deep into the ink-fixing layer so as to be evaporated and diffused, causing color development. By subsequently taking up the transfer sheet into a roll to thereby separate the sheet from the card, the image is formed on the card.
Therefore, when the card is printed, the transfer sheet having the ink image-receiving layer capable of temporarily holding the sublimable dye ink is used as an intermediate, so that a clear image printed by the ink jet printing method can be directly transferred to the ink-fixing layer, that is, to the surface of the card. This makes it possible to efficiently form a clear image, and further protect the image by the ink-fixing layer, which enhances the rub resistance of the printed surface.
Preferably, the step of printing includes printing a mirror image on the transfer sheet such that an image transferred therefrom onto the card forms a normal image.
According to this preferred embodiment, an image transferred onto a card is formed as a normal image.
Preferably, a fluorine film layer is laminated on a surface of the ink-fixing layer of the card.
According to this preferred embodiment, when the transfer sheet is affixed to the card by pressure while applying heat thereto, the ink droplets held in the transfer sheet pass through the fluorine film layer to be diffused and fixed in the ink-fixing layer. The card having the fluorine film layer as the topmost layer thereof protects the image fixed in the ink-fixing layer. Thus, the image is protected by the fluorine film layer similar to a laminating film, whereby the surface of the card is made more excellent in weather resistance, light resistance, heat resistance, rub or abrasion resistance, and chemical resistance due to characteristics of the fluorine film layer, and assume a high gloss.
Preferably, the step of affixing the transfer sheet to the card by pressure while applying heat thereto includes sandwiching the transfer sheet and the card overlaid upon each other between a pair of rollers, and advancing the transfer sheet and the card simultaneously at a constant speed in accordance with rotation of the rollers, at least one of the rollers toward the transfer sheet being a heating roller.
According to this preferred embodiment, a pair of rollers can affix the transfer sheet and the card to each other by applying pressure and heat thereto, while advancing them at a constant speed. In this case, the card is brought into rolling contact with the pair of rollers in a state in line contact therewith along the width of the card (in a direction orthogonal to the direction of feed of the card). This makes it possible to uniformly heat the whole surface of the card and press the card to the transfer sheet stably and uniformly. Consequently, it is possible to prevent degradation of quality of print images due to unevenness of applied heat and pressure. It should be noted that the rollers may be formed by metal rollers formed e.g. of stainless or the like having a predetermined surface smoothness, but more preferably, they are formed by rubber rollers with heat resistance.
Preferably, the step of affixing the transfer sheet to the card by pressure while applying heat thereto includes hot-pressing the image-formed portion of the transfer sheet and the card which are overlaid upon each other.
According to this preferred embodiment, the card has the whole area of its surface uniformly heated and pressed by a hot-pressing method in a state brought into surface contact with the transfer sheet. This makes it possible to ensure intimate contact between the card and the transfer sheet, thereby making it possible to produce an image of high quality. Further, it is possible to heat the card with efficiency.
To attain the above object, according to a third aspect of the invention, there is provided an apparatus for forming an image on a card, comprising:
conveyor means for conveying a card along a transport passage, the card having a substrate layer, an ink-fixing layer laminated on a surface of the substrate layer, and an ink image-receiving layer peelably laminated on a surface of the ink-fixing layer;
printing means arranged to face the transport passage, for printing an image on the card in synchronism with feed of the card by an ink jet printing method by using a sublimable dye ink to thereby cause the sublimable dye ink to be held by the ink image-receiving layer;
heating means arranged to face the transport passage, for applying heat treatment to the printed card to thereby cause diffusion of the sublimable dye ink held in the ink image-receiving layer in the ink-fixing layer to form an image; and
a single casing for accommodating the conveyor means, the printing means, and the heating means.
According to this image forming apparatus, as described above, the ink droplets ejected for printing by the printing means and held in the ink image-receiving layer are thermally treated by the heating means, whereby migration particles of ink at a molecular level are evaporated and diffused deep into the ink-fixing layer, causing color development to form an image. In this case, the printing means and the heating means which are arranged to face the transport passage are accommodated in the single casing together with the conveyor means. Accordingly, these means accommodated in the case are capable of sequentially performing their operations to thereby directly transfer a clear image printed by the ink jet printing method to a surface of the card. This makes it possible to form a clear image on the card with efficiency. Further, it is possible to protect the image without particularly applying pressure thereto, which enhances rub resistance of the printed surface.
It should be noted that after the heat treatment of the card, the ink image-receiving layer is peeled off the card to cause the ink-fixing layer to be exposed. Thus, a card can be produced which is printed with an image with ease and a high durability. Further, it is preferable to form the ink image-receiving layer slightly larger than the ink-fixing layer. This enables the printing means to properly carry out whole surface printing of the card, and allows the ink image-receiving layer to be easily peeled off thereafter.
Preferably, a fluorine film layer is laminated between the ink-fixing layer and the ink image-receiving layer.
According to this preferred embodiment, when the ink image-receiving layer has been peeled off after the heat treatment, the card has the fluorine film layer as the topmost layer for protecting the image fixed in the ink-fixing layer thereof. This provides the image with protection by the fluorine film layer having the characteristics described above.
Preferably, the ink image-receiving layer is formed of a material which is made easily peelable by application of heat.
According to this preferred embodiment, the ink image-receiving layer is made easily peelable by heat treatment by the heating means, and it is easy to peel the ink image-receiving layer off the card.
Preferably, the apparatus further includes card supply means for storing a plurality of the cards in a stacked fashion and supplying the cards one by one to the conveyor means.
According to this preferred embodiment, it is possible to properly feed the cards to the conveyor means one by one while properly controlling the cards, and successively form images on a plurality of cards.
Preferably, the conveyor means includes printer-block conveyor means arranged in a manner associated with the printing means, heater-block conveyor means arranged in a manner associated with the heating means, and transfer means for transferring the card from the printer-block conveyor means to the heater-block conveyor means.
According to this preferred embodiment, the cards are brought to the printing means and the heating means by individual conveyor means, i.e. the printer-block conveyor means and the heater-block conveyor means, and passed or transferred by the transfer means from the printer-block conveyor means to the heater-block conveyor means. This makes it possible to control the feed of the cards individually in a manner associated with the printing means and the heating means, whereby cards can be conveyed in respective fashions suitable for printing and heating.
Preferably, the printer-block conveyor means includes a suction table for sucking and holding the card on a surface thereof by suction air, and a printer-block conveyor belt mechanism for conveying the card via the suction table.
According to this preferred embodiment, the card is transferred in accordance with the movement of the suction table in a state sucked and held horizontally on the suction table. Therefore, the card can be sent along the transport passage properly in a stable manner.
Preferably, the card has an identical laminate structure on both of a front surface and a back surface of the substrate layer, and the printer-block conveyor means is capable of conveying the card in both of a forward direction and a reverse direction, and includes inverting means for inverting the card upside down, the inverting means being arranged either on a proximal end side or on a distal end side of the printer-block conveyor means in a direction of feed of the card in a manner facing the transport passage.
According to this preferred embodiment, after one of the front surface and back surface of the card is printed, the card can be inverted upside down by the inverting means, and sent again by the printer-block conveyor means to print the other of the front surface and back surface of the card.
Preferably, the inverting means includes a catcher capable of receiving the card from the printer-block conveyor means and passing the card to the printer-block conveyor means, an inverting mechanism for inverting the card upside down via the catcher, and a sender roller for sending the card from the catcher.
According to this preferred embodiment, the card is temporarily held by the catcher, inverted by the catcher in a state held thereby, and sent from the catcher by the sender roller. Thus, the catcher is capable of performing reception and passing of the card between the same and the printer-block conveyor means, including inversion of the card.
Preferably, the inverting means also serves as the transfer means, and the sender roller is capable of rotating in both of normal and reverse directions, the catcher being arranged between the printer-block conveyor means and the heater-block conveyor means on the transport passage, and capable of cooperating with the sender roller to send the card in an inverted position to the heater-block conveyor means.
According to this preferred embodiment, the inverting means arranged on a distal end side of the printer-block conveyor means in the direction of transfer of the card also serves as the transfer means, and hence it is possible to simplify the inner construction of the apparatus. Further, when used as the transfer means, the inverting means can send the card to the heater-block conveyor means after restoring the original position of the card before printing. It should be noted that the catcher is preferably configured such that it can weakly hold or retain the lateral ends of the card, so as to prevent the card from falling off.
Preferably, the transfer means includes a catcher arranged on the transport passage between the printer-block conveyor means and the heater-block conveyor means such that the catcher is capable of receiving and passing the card, and a sender roller for sending the card from the catcher to the heater-block conveyor means.
According to this preferred embodiment, the card is passed to the heater-block conveyor means via the catcher cooperating with the sender roller. This enables the printer-block conveyor means and the heater-block conveyor means to properly carry out the feed of the card individually and separately in a state in which the card feeding operation is discontinued between the two conveyor means, and at the same time smoothly transfer the card from the printer-block conveyor means to the heater-block conveyor means.
Preferably, the apparatus further includes control means for controlling the heating means and the heater-block conveyor means, and the control means causes the heater-block conveyor means to convey the card such that the card passes by the heating means being driven for heating, at a constant speed.
According to this preferred embodiment, the card is conveyed at a constant speed in a state brought close to the heating means. Therefore, it is possible to feed and heat the card simultaneously as well as effect uniform heating of the whole surface of the card, thereby preventing degradation of quality of print images due to unevenness of heating.
Preferably, the control means is capable of changing a speed at which the card is conveyed.
According to this preferred embodiment, assuming that the heating temperature is constant, the amount of heat applied can be controlled by changing the speed at which the card is conveyed. This makes it possible to properly heat the card according to the type thereof dependent on the difference in thermal conductivity, or the like.
Preferably, the heating means is formed by a halogen lamp.
According to this preferred embodiment, the heating source implemented by a halogen lamp can be quickly activated, and hence processing time of the image forming process can be shortened. On the other hand, since the halogen lamp is a light source with short wavelengths, heat transmission to the substrate layer of the card can be suppressed. As a result, the surface(s) of the card with the ink image-receiving layer can be properly heated.
Preferably, the heating means is formed by a pair of halogen lamps arranged on opposite sides of the transport passage in a manner parallel and opposed to each other.
According to this preferred embodiment, the card subjected to doubled-sided printing can be thermally treated simultaneously under the same heating conditions.
Preferably, the heater-block conveyor means includes transport guides arranged along the transport passage for guiding the card while supporting the card by left and right side ends of the card, and a pushing mechanism for pushing the card guided by the transport guides, from behind.
According to this preferred embodiment, the card is carried forward while being supported on left-side end and right-side end faces thereof which are not printing surfaces. This makes it possible to send the card with the whole printing surface thereof facing outward (toward a heater device), thereby producing a card printed with an image of high quality and free of unevenness of heating. It should be noted that the transport guides are preferably constructed by a plurality of rotatably free rollers.
Preferably, the pushing mechanism is formed by a heater-block conveyor belt mechanism having pushing pawls formed on a surface thereof.
According to this preferred embodiment, the card has one of the pushing pawls brought into abutment with a trailing edge portion thereof, and at the same time is carried forward in accordance with belt conveyance of the pushing pawls. Therefore, the card can be transferred smoothly and suitably by the simple construction of the pushing pawls in a manner pushed from behind.
Preferably, the heating means is formed by a pair of halogen lamps arranged on opposite sides of the transport passage in a manner parallel and opposite to each other, and the heater-block conveyor belt mechanism having a conveyor belt stretched for revolving around one of the halogen lamps.
According to this preferred embodiment, it possible to increase the freedom of suitable arrangement of the halogen lamps. It should be noted that the conveyor belt is formed by a heat resistant silicone.
Preferably, the conveyor belt of the heater-block conveyor belt mechanism is stretched such that the conveyor belt faces a magnetic encoder portion of the card carried thereon.
According to this preferred embodiment, the card is transferred with its magnetic encoder portion facing the conveyor belt. This makes it possible to arrange the heater-block conveyor belt at a location opposed to the path of a portion of the card not requiring heat irradiation for fixing and forming an image. It should be noted that the ink image-receiving layer of the card may be configured to be uniformly laminated on the surface of the card including the magnetic encoder portion thereof, or alternatively, the same may be configured to be partially laminated on the surface of the card except the magnetic encoder portion thereof. In the latter case, since the conveyor belt blocks heat irradiation to the magnetic encoder portion of the card, it is possible to prevent thermal influence of heating against the magnetic encoder portion.
To attain the above object, according to a third aspect of the invention, there is provided another apparatus for forming an image on a card, comprising:
sheet feed means for feeding a transfer sheet along a traveling passage, the transfer sheet having a substrate layer, and an ink image-receiving layer laminated on a surface of the ink image-receiving layer;
printing means arranged to face the traveling passage, for printing an image on the transfer sheet in synchronism with feed of the transfer sheet by an ink jet printing method by using a sublimable dye ink;
card conveyor means for conveying a card along a transport passage, the card having a substrate layer, and an ink-fixing layer laminated on a surface of the substrate layer; and
thermal pressing means arranged to face a confluent portion of the traveling passage and the transport passage, for affixing the transfer sheet to the card by pressure while applying heat thereto, with an image-formed portion of the transfer sheet and the ink-fixing layer of the card being positioned and overlaid upon each other, thereby causing diffusion of the sublimable dye ink held in the ink image-receiving layer in the ink-fixing layer and color development to form an image; and
peeling means arranged at a location downstream of the thermal pressing means, for peeling the transfer sheet off the card; and
a single casing for accommodating the sheet feed means, the printing means, the card conveyor means, the thermal pressing means, and the peeling means.
According to this image forming apparatus, a transfer sheet having an ink image-receiving layer formed thereon is employed to form a print image on a card. In this case, when an image is directly printed on the transfer sheet sent along the traveling passage by the ink jet printing method using the sublimable dye ink, ink droplets are impregnated into the ink image-receiving layer and held therein. Then, a portion formed with the image in the form of the ink droplets is positioned on the card, and the transfer sheet is affixed to the card by pressure in a state of the sheet and card overlaid upon each other while applying heat thereto, whereupon from the portion formed with the image, particles of ink at a molecular level are thermally transferred or migrated deep into the ink-fixing layer so as to be evaporated and diffused, causing color development. By subsequently taking up the transfer sheet into a roll to thereby separate the sheet from the card, the card having the image fixed in a surface thereof is provided.
In this case, the sheet feed means and other means are accommodated in a single casing, and a clear image can be formed in a surface of the card through a sequence of operations by these means in the casing. This makes it possible to efficiently form the clear image on the card.
It should be noted that it is preferable that the ink image-receiving layer is slightly larger than the ink-fixing layer. This enables the printing means to properly carry out whole surface printing on the card.
Preferably, the printing means prints a mirror image of the image on the transfer sheet such that an image transferred therefrom onto the card forms a normal image.
According to this preferred embodiment, an image transferred onto a card is formed as a normal image.
Preferably, a fluorine film layer is laminated on a surface of the ink-fixing layer of the card.
According to this preferred embodiment, when the transfer sheet is affixed to the card by pressure while applying heat to them, the ink droplets held in the transfer sheet pass through the fluorine film layer to be diffused and fixed in the ink-fixing layer. The card having the fluorine film layer as the topmost layer thereof protects the image fixed in the ink-fixing layer. Thus, the image comes to be protected by the fluorine film layer which provides a laminating film, and the surface of the card is made more excellent in weather resistance, light resistance, heat resistance, rub or abrasion resistance and chemical resistance due to characteristics of the fluorine film layer, and assume a high gloss.
Preferably, the apparatus further includes card supply means for storing a plurality of the cards in a stacked fashion and supplying the cards one by one to the card conveyor means.
According to this preferred embodiment, it is possible to properly feed the cards to the card conveyor means one by one while controlling the cards with ease, and bring a plurality of cards to the transfer sheet successively. It should be noted that the card supply means may be accommodated in the single casing.
Preferably, the sheet feed means includes a supply reel for unrolling a roll of the transfer sheet wound therearound, and a take-up reel for taking up the transfer sheet unrolled, and the transfer sheet is unrolled from the supply reel, sent along the traveling passage, peeled off the card, and then taken up by the take-up reel.
According to this preferred embodiment, it is possible to provide the transfer sheet in the form of a roll, thereby making it possible to carry out printing on the transfer sheet continuously. Therefore, unused and used transfer sheets can be managed easily. It should be noted that the take-up reel is used as a part of the peeling means.
Preferably, the traveling passage is formed by a cartridge casing, and the supply reel, the take-up reel, and the transfer sheet are accommodated in the cartridge casing to form a sheet cartridge.
According to this preferred embodiment, it becomes possible to facilitate handling of the apparatus, such as storage of the transfer sheet, and the like, when the apparatus is transported. Further, when a transfer sheet is used up, another transfer sheet can be provided easily by replacement of the sheet cartridge accommodating the transfer sheet.
Preferably, the thermal pressing means comprises a pair of rollers which sandwich the transfer sheet and the card overlaid upon each other therebetween, and advances the sheet and the card at a constant speed in accordance with rotation thereof, at least one of the rollers toward the transfer sheet being a heating roller.
According to this preferred embodiment, a pair of rollers can affix the transfer sheet and the card to each other by application of pressure and heat thereto, while advancing them at a constant speed. In this case, the card is brought into rolling contact with the pair of rollers in a state in line contact therewith along the width of the card (in a direction orthogonal to the direction of feed of the card). This makes it possible to uniformly heat the whole surface of the card and press the card to the transfer sheet stably and uniformly. Consequently, it is possible to prevent degradation of quality of print images due to unevenness of applied heat and pressure. It should be noted that the rollers may be formed by metal rollers formed e.g. of stainless or the like having a predetermined surface smoothness, but more preferably, they are formed by rubber rollers with heat resistance.
Preferably, the thermal pressing means is formed by a hot-pressing mechanism for sandwiching an image-formed portion of the transfer sheet and the card overlaid upon each other, and applying heat thereto.
According to this preferred embodiment, the card has the whole area of its surface uniformly heated and pressed by a hot-pressing method in a state brought into surface contact with the transfer sheet. This makes it possible to ensure intimate contact between the card and the transfer sheet, thereby making it possible to produce an image of high quality. Further, it is possible to heat the card with efficiency.
The above and other objects, features, and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.